When Dairy Intolerance Joins Celiac Disease

The difficulty digesting milk products that stems from celiac damage is called secondary lactose intolerance. Green says the good news is that once you eliminate gluten from your diet (the only current treatment for celiac disease), your small intestine begins to heal and eventually, you may be able to have dairy products again. This was the case for Dennis, who today only abstains from dairy because it makes her feel congested.

Green notes that it may take six months or longer on the gluten-free diet for celiac patients to develop tolerance, and you may not tolerate dairy in the same quantities as before.

“Try a bit of hard cheese or some yogurt and see how that goes. If that works, try something else,” he says. “Try a lactase tablet to help digestion. Some people find that’s all they need.”

Lactose intolerance may not be the only other digestive issue. At the Columbia center, most of Green’s patients have persistent symptoms after they go gluten-free. “We go through a checklist with them because there are a number of possible causes for this, from lactose or fructose (fruit sugar) intolerance to bacterial overgrowth, where bacteria are present in the small intestine when they shouldn’t be,” he says.

Get the Breath Test

Green stresses the need for a breath test to confirm lactose intolerance. It is a simple procedure, like a really long roadside breathalyzer in which the patient drinks a beverage that contains lactose and then blows into a small, narrow plastic bag every 15 minutes or so over two to three hours.

The bag is then attached to a machine that measures gases such as hydrogen and methane, which are not supposed to be in the small intestine. If they are, it’s proof that the digestion of the lactose molecule has been ever so rudely interrupted.

The importance of a breath test is underscored by the fact that the form of lasting intolerance, primary lactase deficiency, is also common, especially in older adults. Prevalence studies have had varying results, but the National Institutes of Health estimates that between 30 and 50 million Americans have lactose intolerance.